1978 Evinrude 2hp.

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    russ


    Replies: 24
    Topics: 31
    #218672

    Have this little motor that will not start. Did have it going for about 5 secs. Lots of spark high speed set at 3/4 low speed set at 1 1/2. With choke on I can pull till the skin comes of my finger.It may sneeze or a little backfire but will not start,Have tried more plugs with same result.Have sprayed gas in cylinder still no go. Did a compression test twice and got a 56psi reading.Does anyone have something else I can try. Maybe compression to low. Any help would be greatly appreciated Thanks. Russ….

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    fleetwin

    US Member - 2 Years
    Replies: 3481
    Topics: 52
    #218674

    Well, 56PSI is pretty low for that engine…It won’t fire even when you squirt fuel/oil into the cylinder? When was the last time it ran OK? How long has it been sitting since then? Compression readings are often false on these little combustion chambers, you might try a different gage…
    Once the compression reading is confirmed, you might want to pull the head if compression is still low…Maybe it is just blown head gasket….Be sure water hasn’t entered the cylinder, squirt plenty of oil in there to keep rust away…

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    russ


    Replies: 24
    Topics: 31
    #218681

    Maybe has been sitting for a while not to sure.Compression tester is good. What should the psi be in this little motor? Does not matter what I do just get a little baby sneeze.

    Ken Smith
    Ken Smith

    Canada Member - 2 Years
    Replies: 48
    Topics: 11
    #218693

    I have a ’74 2 HP Johnson and a ’76 2 HP Johnson. Both have 100 and 110 PSI . 56 psi is way to low. Ken

    www.kenadianoutboards.com

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    fleetwin

    US Member - 2 Years
    Replies: 3481
    Topics: 52
    #218695

    Your compression tester is probably good, the problem might be the location of the release valve…Keep in mind, that is a very small combustion chamber…So, the longer the hose, the less accurate the reading will be…
    That being said, I don’t think it is a gage problem either… When was the last time it ran OK? Might be time to pull the head/exhaust cover…

    frankr
    frankr


    Replies: 5362
    Topics: 48
    #218700

    Two bolts will remove the lower unit (to protect the water pump). Now will it start out of the water? If it does, it is a pretty good clue that the motor is worn out (or low compression for whatever reason).

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    crosbyman

    Canada Member - 1 Year
    Replies: 1668
    Topics: 199
    #218715

    my brother had a 2hp….little critter always was a problem for some reason…. this is years ago mind you I know he even found a cracked carb body does yours at least sputter with fresh gas in the cyl. ??? you did not elaborate much .

    was did you do clean up wise…??

    . did you do the carb orifices, clean & adj the point… th float etc.. is the condenser shorted if you do a ohms reading on it ( a analog dial meter should show low resistance working slowly back up way up to infinity as the condenser charges up. not a foolproof test but better than a short !

    can you feel good suction on the carb face if a friend pull starts for you

    keep at it… patiience brings joy 🙂 btw lots of sparks is great … what about long sparks…around 5/16″ ??

    Joining AOMCI has priviledges 🙂

    • This reply was modified 1 week, 2 days ago by Avatarcrosbyman.
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    billw

    US Member - 2 Years
    Replies: 1312
    Topics: 42
    #218725

    I just resurrected a 1981 2 hp, for a coworker. It checked in at 115 psi compression. I agree that 56 psi is way too low. It makes you wonder how it even ran long enough to GET that low. It also makes me think Fleetwin is on to something, with a bad head gasket. It happens, especially if the engine had been overheated. Then again, if somebody ran it on 100:1 fuel mix, or maybe even zero to one (oops) then, yeah, it could have gotten down to 56 psi pretty easy. Either way, I’d take the head off and see what you find.

    Long live American manufacturing!

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    russ


    Replies: 24
    Topics: 31
    #218729

    Was using 50/1 mix.Did not fire when I put fuel in cylinder. Spark tester lights up fuel is fresh . Going to drop lower unit this morning when frost is gone. No heat in garage.Thank you all for your input. Will post later what I find.

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    crosbyman

    Canada Member - 1 Year
    Replies: 1668
    Topics: 199
    #218731

    get a spark tester with a adjustable gap to confirm STRONG AND LONG spark !! if yours is just the flasher type confirm spark jumps 5 /16 something is weird…. gas fumes should at least explode

    if you put gas in the cyl. my 9.5 turtle works fine at 65PSI if you are not plannig to spend $$$$ at least get it to poof…then feed it a good shot decarb or seafoam

    jmho

    Joining AOMCI has priviledges 🙂

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    russ


    Replies: 24
    Topics: 31
    #218735

    Have sprayed different cleaners thru. Took lower end off still no start. Put piston at tdc and put some carb cleaner on top left for 10 min lifted motor up to dump out cleaner nothing came out. Put back in vice carb cleaner coming out lower end.Tried to start again and got a little flame out bottom after 10 pulls.Re checked compression 55 psi.

    Tubs
    Tubs

    US Member - 1 Year
    Replies: 3233
    Topics: 175
    #218737

    Another compression is too low.

    You're only as smart as the person you're talking to.

    • This reply was modified 1 week, 1 day ago by TubsTubs.
    Mumbles
    Mumbles

    Canada Member - 2 Years
    Replies: 4596
    Topics: 437
    #218775

    This two horse had a blown head gasket and the escaping fire burned a groove into the head and the top of the cylinder. A piece of aluminum casting was also missing from the cylinder in the same area so it took a bit of machining to get both surfaces into acceptable condition again.

    DSC00175

    DSC00186

    Another problem with these motors is the crankshaft seals. Dealer says you have to buy the lower case half with the bearing and seal already installed as a unit. Not so. The bearing and seal can be pressed out and replaced as needed. No matter what anyone says, leaking crank seals do not contribute to the cylinders low pressure. That is governed by the condition of the cylinder itself and the piston and rings.

    DSC00183

    • This reply was modified 1 week, 1 day ago by MumblesMumbles.
    • This reply was modified 1 week, 1 day ago by MumblesMumbles.
    • This reply was modified 1 week, 1 day ago by MumblesMumbles.
    • This reply was modified 1 week, 1 day ago by MumblesMumbles.
    • This reply was modified 1 week, 1 day ago by MumblesMumbles.
    Avatar
    russ


    Replies: 24
    Topics: 31
    #218784

    Thanks mumbles and everyone else for help. Will check out head gasket before I do any more. Thanks Russ…

    frankr
    frankr


    Replies: 5362
    Topics: 48
    #218787

    mumbles wrote, ” No matter what anyone says, leaking crank seals do not contribute to the cylinders low pressure. That is governed by the condition of the cylinder itself and the piston and rings.”. That is true, BUT many do not realize that crankcase compression is also important in a two-stroke. Worn bearings and seals can make a non-runner, as mumbles also suggested.

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